Science

A team of European astronomers have announced a new milestone in the field of extrasolar planets. Using the technology of HARPS, the most accurate in the calculation of radial velocities, have found three systems of Super Earths around the star HD 40307.

We will explain what is a super-Earth. Are so-called extrasolar planets, with more massive than Earth, with no more than ten times their mass and in turn have a composition similar to that of our planet.

Looking more closely at the sample studied with HARPS, the astronomers have counted a total of 45 candidate planets with a mass less than thirty times that of Earth and a translational period smaller than 50 days. This implies that a Sun-like star takes charge of them.

" 'Houses' each star planets and, if so, how?" Asks the hunter of planets Michel Mayor. "You may still not be able to answer that question, but we haciengo great strides toward that."

Since the discovery in 1995 of a planet around the star 51 Pegasi by Mayor and Didier Queloz, more than 270 exoplanets have been found, mostly around stars like the sun Most of these planets were giants like Saturn and Jupiter , and current statistics show that one in fourteen stars harbor such planets.

"Thanks to the telescope equipped with the HARPS spectrograph at La Silla (Chile), we can now discover smaller planets, with mass between two and ten times that of Earth."

The group of astronomers who announced the discovery at an international conference, has discovered a system of three super-Earths around a star slightly less heavy than the Sun, and is located 42 light-years. These planets are 4.2, 6.7 and 9.4 times the mass of Earth, orbiting around its star every 4.3, 9.6 and 20.4 days, respectively.

At the same conference, astronomers announced the discovery of two other planetary systems, also with the HARPS instrument. In one, a super-Earth (7.5 times the mass of our planet) orbiting the star HD 181433 in 9.5 days. This star also hosts a Jupiter-like planet. In the other system have discovered a planet 22 times the mass of Earth and a planet like Saturn.

It's easier to find planets that have a period shorter than one translation has it long. "There are probably many more planets, not only super-Earth or planets that resemble Neptune, but also very similar planets to Earth We can not detect at the moment. "

Source: Eurekalert.com

Image: BBC

A 4500 meters high on a desolate plateau of the Himalayas Tibet, a group of international researchers led by geologist Yang Wang was surprised to find thick layers of lake sediment filled with plants, fish and animal fossils typical of a much lower elevation and climate wetter and warmer.

So what are today the world's highest mountains were not 2 or 3 million years, when they were at a much lower and some were a snowcapped mountain, but a lake.

Scientists was University Florida, and when they returned there with samples, subjected to analysis of carbon and oxygen isotopes. Not only could know the age of the fossils of animals, but what they ate plants, many.

They could also discover the reason for its extinction in the area, a dramatic change in the weather does between 2 and 3 million years.

Today the Tibetan Plateau is all rock, desert, no trees, barely supporting grass-freezing weather. The discovery that 3 million years ago conditions in the same region were completely different makes scientists think of a really surprising possibility: major changes tectonics in the Tibetan Plateau may have caused the elevation of this region is much less time than thought .

This might even rethink the methods of geology to reconstruct the history of uplift of the region. It was previously believed that the present Tibetan plateau was the result of geological and climatic changes 50-60 million years ago.

"The region also is thought to be important for the monsoon rains in Asia, controlling the environment over much of Asia," Yang said. "The chronology of the rise of the Tibetan Plateau and its climatic and biotic consequences have been the subject of much debate and speculation because many of the spectacular mountains, glaciers and gorges of Tibet have been almost no human presence and geologically unexplored," continued Yang .

He concludes that "many of the places I've visited in Tibet are now deserts, and they continue to find deposits of lake sediments with abundant fish and shells fósils. This raises the question what came first, and caused the disappearance of these lakes? "The tectonic shift? Or a global climate change?

Source: ScienceDaly

Image: Wikipedia

As we collect the ScienceDialy, the Sun has been two years without producing sunspots and giving a break to satellites.

This is a discussion point for scientists who come together these days in the International Solar Conference at the University of Montana. About one hundred scientists from Europe, Asia, Africa and America have met to talk about the "solar variability, climate on Earth and the space environment.

The periods of solar inactivity are common, scientists say, but it is still too long. "It seems to be dead," said Saku Tsuneta of the Hinode mission, "but this is only a small concern, very small.

The Hinode mission is a Japanese project that has the support of the U.S. and the UK. It consists of a satellite equipped with three telescopes that shows changes in the surface of the Sun through its atmosphere. The satellite orbit about 500 kilometers above the surface of the sun and provides an uninterrupted view of the sun for several months.

Dana Longcope, a solar physicist, says that our sun operate normally by following a cycle of 11 years, where the peak occurs mid-cycle. Therefore, the minimum activity occurs in the cycle changes. This activity is composed of sunspots, flares and the 'fire' lots. The previous cycle reached its zenith in 2001 and believes it should be ending now. The next peak of activity would occur in 2012. However, the sun is as inactive as two years ago, and scientists do not know why.

"It'sa dead face," Tsuneta said referring to the appearance of our star.

Scientists make clear that they are not as meteorologists. They can not predict the future, simply have the ability to observe and have observed that this period of inactivity is too long, longer than usual. Four centuries ago, between 1650 to 1700, the Sun was 50 years without producing sunspots, just as on Earth there was a small "ice age" which lasted from the fifteenth century and the mid century.

Tsuneta said to have no idea when he will be active the Sun, but scientists associated with the Hinode mission expected it to regain peak. New stations have been receiving signals from Hinode in India, Norway, Alaska and South Pole. All this requires international cooperation. "No country has the capacity to do this on your own," says Tsuneta. The Hinode mission is conducted by four countries, three space agencies and eleven organizations working together since September 2006. Contributors include Loren Acton, research professor and former colleague of Tsuneta. In its 72 years, Acton is our star and excited about the new mysteries involved. In fact, says wish to continue on the crest of the wave in 20 years.

Source: ScienceDialy

Image: ScienceDialy (courtesy of NASA)

A study carried out at 100,000 mobile phones across Europe shows that we are creatures of habit, even though we try to show otherwise.

The study suggests that most people can be found in a few locations, usually not far from home. With the routine of our daily lives is what makes sense, something we like both sporadic breakaways.

"We're pretty normal, because we always return to the same places, like home or work," says one researcher.

This may seem obvious, but researchers say their work could open new frontiers in urban planning. The data were obtained from a European company mobile phone contract that prevents researchers publish the country in which it operates. It followed 100,000 mobile data among 6 million people for six months. The location of each subject was revealed every time he made or received a call or message, as the company recorded the nearest phone tower and the time at which the connection was made. As the calls and messages were very sporadic, the investigators collected data with another system the locations of 206 users every two hours. Both studies were very similar.

Total, which has been discovered that the human being does not move much, although users who traveled over 1,000 miles were not included in the study. Mobile was chosen for study because it is much more reliable than money or credit cards.

The negative part of the study is the lack of user privacy, even if it has kept its anonymity, which makes it a challenging study. "Raises questions about the protection of privacy in physical spaces when the device manages to capture the location of each one, "says Marc Rotenberg, Electronic Privacy Center in Washington. Arthur Caplan, director of the Center for Bioethics, goes further: "the investigators are free to observe people in public places without permission, but the mobile phone is not something we consider a public entity."

Image: Flickr.com

Source: NYTimes.com